Liquid crystalline medium and method for manufacturing liquid crystal display panel

ABSTRACT

A liquid crystalline medium comprises a plurality of polymerizable monomers and a plurality of liquid crystal molecules. The liquid crystal molecules are selected from at least one of compounds 1, 2, 3, 4, 5, and 6. 
     
       
         
         
             
             
         
       
     
     “G 1 ”, “G 3 ” and “G 5 ” are independently alkyl having 1 to 8 carbons or alkyenyl having 2 to 8 carbons. “G 2 ” and “G 6 ” are independently alkyl having 1 to 8 carbons or alkoxy having 1 to 7 carbons. “G 4 ” is alkyl of 1 to 8 carbons, alkyenyl of 2 to 8 carbons or alkoxy of 1 to 7 carbons. “Z 1 ” is single bond, ethyl or methoxy. “Z 2 ” is single bond, ethyl, methoxy, or caroboxyl. “Z 3 ” is single bond, ethyl, difluoromethoxy, difluoropropoxy or ethyl carboxyl. “Z 4 ” is single bond, ethyl, difluoromethoxy, or difluoropropoxy. 
     
       
         
         
             
             
         
       
     
     are independently 1,4-cyclohexylene or 1,4-phenylene. One of “E 1 ” and “E 2 ” is fluorine, and the other is chlorine.

This application is a divisional application of co-pending applicationSer. No. 12/000,970, filed on Dec. 19, 2007.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates in general to a liquid crystalline medium, aliquid crystal display panel using the same, and a method formanufacturing a liquid crystal display panel, and more particularly to aliquid crystalline medium which is capable of being applied to apolymer-stabilizing alignment (PSA) technology, a liquid crystal displaypanel using the same, and a method for manufacturing a liquid crystaldisplay panel.

2. Description of the Related Art

Polymer-stabilizing alignment (PSA) technology has been developedrecently in the field of liquid crystal display panels. Polymerizablemonomers are added into a liquid crystal layer, and would be arranged bythe liquid crystal molecules when an electric field is applied. Thesearranged monomers are polymerized into alignment polymers under exposureof heat or irradiation of ultraviolet. The alignment polymers is foraligning liquid crystal molecules, especially when no electric field isapplied to the LCD panel.

However, not all the liquid crystalline media are suitable for beingapplied to PSA technology. Therefore, it is very important to develop aliquid crystalline medium not only suitable for being applied to PSAtechnology but also having good optical performance of the liquidcrystal display panel.

SUMMARY OF THE INVENTION

The invention is directed to a liquid crystalline medium, a liquidcrystal display panel using the same and a method for manufacturing aliquid crystal display panel. The liquid crystalline medium of thepresent invention, including liquid crystal molecules and polymerizablemonomers, is suitable for being applied to polymer-stabilizing alignmenttechnology. The liquid crystal display panel comprising above mentionedliquid crystalline medium and manufactured by PSA technology has fasterresponse speed.

According to the present invention, a liquid crystalline mediumincluding several polymerizable monomers and several liquid crystalmolecules is provided. The liquid crystal molecules are selected from atleast one of compounds 1, 2, 3, 4, 5 and 6.

“G¹”, “G³” and “G⁵” are independently alkyl having 1 to 8 carbons oralkyenyl having 2 to 8 carbons. “G²” and “G⁶” are independently alkylhaving 1 to 8 carbons or alkoxy having 1 to 7 carbons. “G⁴” is alkylhaving 1 to 8 carbons, alkyenyl having 2 to 8 carbons or alkoxy having 1to 7 carbons. “Z¹” is single bond, ethyl, or methoxy. “Z²” is singlebond, ethyl, methoxy or caroboxyl. “Z³” is single bond, ethyl,difluoromethoxy, difluoropropoxy or ethyl carboxyl. “Z⁴” is single bond,ethyl, difluoromethoxy or difluoropropoxy.

are independently 1,4-cyclohexylene or 1,4-phenylene. One of “E¹” and“E²” is fluorine, and the other is chlorine.

According to the present invention, a method for manufacturing a liquidcrystal display panel including following steps is provided. First, anupper substrate and a lower substrate are provided in a step (a). Next,a space between the upper substrate and a lower substrate is filled withthe above-described liquid crystalline medium. Then, an electric fieldis applied to the upper substrate and the lower substrate, and an energysource is provided for polymerizing the polymerizable monomers intoalignment polymers.

According to the present invention, a liquid crystal display panelincluding a lower substrate, an upper substrate and a liquid crystallayer between the upper substrate and the lower substrate is provided.The liquid crystal layer includes the above-described liquid crystalmolecules and several alignment polymers. The alignment polymers arepolymerized by the above-described polymerizable monomers and formed onat least one of the upper substrate and the lower substrate.

The invention will become apparent from the following detaileddescription of the preferred but non-limiting embodiments. The followingdescription is made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a comparison chart illustrating driving voltage versus turn-ontime (T_(on)) of a liquid crystal display panel according to a preferredembodiment of the present invention;

FIG. 2 is a comparison chart illustrating driving voltage versusturn-off time (T_(off)) of the liquid crystal display panel according tothe preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a liquid crystalline medium includingliquid crystal molecules and polymerizable monomers. Liquid crystaldisplays, comprising the liquid crystalline medium of the invention andmanufactured by polymer-stabilizing alignment (PSA) technology, haveshorter response time. The formulas and mixture ratio of the liquidcrystal molecules and the polymerizable monomers in the liquidcrystalline medium are illustrated first, and a method for manufacturinga liquid crystal display panel using the liquid crystalline medium ofthe present invention is illustrated later.

The liquid crystalline medium of the present invention includes numerousliquid crystal molecules and numerous polymerizable monomers. The liquidcrystal molecules of the present invention are selected from at leastone of compounds 1, 2, 3, 4, 5, and 6.

The compound 1 is represented as following formula.

The compound 2 is represented as following formula.

The compound 3 is represented as following formula.

The compound 4 is represented as following formula.

The compound 5 is represented as following formula.

The compound 6 is represented as following formula.

“G¹”, “G³” and “G⁵” are independently alkyl having 1 to 8 carbons oralkyenyl having 2 to 8 carbons.

“G²” and “G⁶” are independently alkyl having 1 to 8 carbons or alkoxyhaving 1 to 7 carbons.

“G⁴” is alkyl having 1 to 8 carbons, alkyenyl having 2 to 8 carbons oralkoxy having 1 to 7 carbons.

“Z¹” is single bond, ethyl (—C₂H₄—) or methoxy (—CH₂O—).

“Z²” is single bond, ethyl (—C₂H₄—), methoxy (—CH₂O—) or caroboxyl(—COO—).

“Z³” is single bond, ethyl (—C₂H₄—), difluoromethoxy (—CF₂O—),difluoropropoxy (—OCF₂C₂H₄—) or ethyl carboxyl (—C₂H₄COO—).

“Z⁴” is single bond, ethyl (—C₂H₄—), difluoromethoxy (—CF₂O—) ordifluoropropoxy (—OCF₂C₂H₄—).

are independently 1,4-cyclohexylene or 1,4-phenylene.

One of “E¹” and “E²” is fluorine, and the other is chlorine.

In a preferred embodiment, the liquid crystal molecules in the liquidcrystalline medium of the present invention include liquid crystalmolecules including chlorine. The liquid crystal molecules preferablyinclude at least three compounds. The liquid crystal moleculespreferably include at least one selected from the compounds 1 or 2, atleast one selected from the compounds 3 or 4, and at least one selectedfrom the compounds 5 or 6. For example, the liquid crystal moleculesinclude at least one of compounds selected from the group consisting ofa compound [1-1] belonging to the compound 1 and compounds [2-2], [2-3],[2-4] and [2-5] belonging to the compound 2.

The compound [1-1] belongs to the compound 1. In the compound [1-1],“G¹” is propyl (alkyl having 3 carbons), and “G²” is ethyloxy (alkoxyhaving 2 carbons). “Z¹” is single bond. “E¹” is fluorine. “E²” ischlorine.

The compounds [2-1], [2-2], [2-3]. [2-4] and [2-5] belong to thecompound 2. “G¹” of the compound [2-1] is ethyl (alkyl having 2carbons). “G²” of the compound [2-1] is ethyloxy (alkoxy having 2carbons). “Z¹” of the compound [2-1] is single bond. “E¹” of thecompound [2-1] is fluorine. “E²” of the compound [2-1] is chlorine.

of the compound [2-1] is 1,4-cyclohexylene. In the compound [2-2], “G¹”is propyl (alkyl having 3 carbons), and the rest of the functionalgroups in the compound [2-2] are the same as those in the compound[2-1]. In the compound [2-3],

is 1,4-phenylene, and the rest of the functional groups in the compound[2-3] are the same as those in the compound [2-2]. In the compound[2-4], “G¹” is butyl (alkyl having 4 carbons), and the rest of thefunctional groups in the compound [2-4] are the same as those in thecompound [2-1]. In the compound [2-5], “G¹” is pentyl (alkyl having 5carbons), and the rest of the functional groups in the compound [2-5]are the same as those in the compound [2-1].

The liquid crystal molecules include at least one of compounds selectedfrom the group consisting compounds [3-1], [3-2] and [3-3] belonging tothe compound 3 and compounds [4-1] and [4-2] belonging to the compound4.

The compounds [3-1], [3-2] and [3-3] belong to the compound 3. “G³” ofthe compound [3-1] is propyl (alkyl having 3 carbons). “G⁴” of thecompound [3-1] is ethyloxy (alkoxy having 2 carbons).

of the compound [3-1] is 1,4-phenylene. In the compound [3-2], “G³isbutyl (alkyl having 4 carbons). “G⁴” of the compound [3-2] is propyl(alkyl having 3 carbons).

of the compound [3-2] is 1,4-cyclohexylene. “G³” of the compound [3-3]is pentyl (alkyl having 5 carbons). In the compound [3-3], “G⁴” is ethyl(alkyl having 2 carbons), and the rest of the functional groups in thecompound [3-3] are the same as those in the compound [3-2].

The compounds [4-1] and [4-2] belong to the compound 4. “G³” of thecompound [4-1] is propyl (alkyl having 3 carbons). “G⁴” of the compound[4-1] is methyl (alkyl having 1 carbon).

of the compound [4-1] is 1,4-cyclohexylene. “Z²” of the compound [4-1]is single bond. In the compound [4-2], “G⁴” is methoxy (alkoxy having 1carbon), and the rest of the functional groups of the compound [4-2] arethe same as those of the compound [4-1].

The liquid crystal molecules further include at least one selected fromthe group consisting of compounds [5-1] and [5-2] belonging to thecompound 5 and a compound [6-1] belonging to the compound 6.

The compounds [5-1] and [5-2] belong to the compound 5. “G⁵” of thecompound [5-1] is propyl (alkyl having 3 carbons). “G⁶” of the compound[5-1] is ethyloxy (alkoxy having 2 carbons).

of the compound [5-1] is 1,4-cyclohexylene. “Z³” of the compound [5-1]is ethyl. In the compound [5-2], “G⁵” is pentyl (alkyl having 5carbons), and the rest of the functional groups of the compound [5-2]are the same as those of the compound [5-1].

The compound [6-1] belongs to the compound 6. “G⁵” of the compound [6-1]is pentyl (alkyl having 5 carbons). “G⁶” of the compound [6-1] isethyloxy (alkoxy having 2 carbons).

of the compound [6-1] is 1,4-cyclohexylene. “Z⁴” of the compound [6-1]is single bond.

The polymerizable monomers of the liquid crystalline medium of thepresent invention preferably are selected from one of compounds I, II,III, IV and V. The compound I is represented as following formula.

The compound II is represented as following formula.

The compound III is represented as following formula.

The compound IV is represented as following formula.

The compound V is represented as following formula.

“R” is hydrogen, fluorine, chlorine, cyano group (—CN), thiocyanato(—SCN), pentafluoro-sulfanyl (—SF₅), nitrite (—NO₂), straight chain orbranched chain alkyl group or a “X₂-(Sp₂)_(v)-P₂” group, in which v≧0.In the above-described straight chain or branched chain alkyl group, oneor two nonadjacent —CH₂— groups can be replaced by oxygen, sulfur,vinylene (—CH═CH—), carbonyl (C═O), caroboxyl (—COO—), carbothio (S—CO—,—CO—S—) or alkyne.

“X¹” and “X²” are independently oxygen, sulfur, methyoxy (—OCH₂—),carbonyl (C═O), caroboxyl (—COO—), carbamoyl (—CO—N⁰R—, —N⁰R—CO—),methylthio (—CH₂S—, —SCH₂—), ethenylcarbonyl (—CH═CH—COO—),carbonylethenyl (—COO—CH═CH—) or single bond.

“Sp₁” and “Sp₂” are independently a spacer group or single bond.

“L_(m)” and “L_(n)” are hydrogen, fluorine, chlorine, cyano group,alkyl, alkylcarbonyl, alkoxycarbonyl, or alkylcarbonyloxy having 1 to 7carbons respectively. m≧1 and n≧1. One or more hydrogen atoms in theabove-described alkylcarbonyl can be replaced by fluorine or chlorine.

“Q₁” and “Q₂” are independently oxygen, sulfur, (carbonyl, C═O),caroboxyl (—COO—), methyoxy (—OCH₂—), methylthio (—CH₂S—),ethenylcarbonyl (—CH═CH—COO—), carbonylethenyl (—COO—CH═CH—),difluoromethoxy (—CF₂O—, —OCF₂—), difluoro methylthio (—CF₂S, —SCF₂—),ethyl (—C₂H₄—), difluoroethane (—CF₂CH₂—, —CH₂CF₂—), tetrafluoroethane(—CF₂CF₂—), vinylene (—CH═CH—), difluoroethenylene (—CF═CF—), ethynyl(—C≡C—) or single bond.

“P₁” and “P₂” are polymerizable groups respectively. The polymerizablegroups can be selected from at least one of groups VI, VII, VIII. IX andX.

The formula of the group VI is shown as follow.

The formula of the group VII is shown as follow.

The group VIII is pyrrole-2,5-dione, and the formula of the group VIIIis shown as follow.

The formula of the group IX is shown as follow.

The formula of the group X is shown as follow.

“U”, “T”, “Y” and “M” are independently selected from hydrogen, methyl,fluorine, trifluoromethyl (—CF₃) and phenyl.

The above-described polymerizable monomers can be following compounds[P-1], [P-2], [P-3] and [P-4].

The polymerizable monomers [P-1] and [P-2] belong to the compound II.“L_(m)” of the polymerizable monomer [P-1] is hydrogen. m=4. w=0. “R” ofthe polymerizable monomer [P-1] is X₂-(Sp₂)_(v)-P₂ group. v=0. “X₁” and“X₂” of the polymerizable monomer [P-1] are single bond. “P₁” and “P₂”of the polymerizable monomer [P-1] are the group IX. “Y” of thepolymerizable monomer [P-1] is methyl. “L_(m)” of the polymerizablemonomer [P-2] is hydrogen. m=4. w=0 In addition, “R” of thepolymerizable monomer [P-2] is X₂-(Sp₂)_(v)-P₂ group. v=0. “X₁” and “X₂”of the polymerizable monomer [P-2] are oxygen. “P₁” and “P₂” of thepolymerizable monomer [P-2] are the group X. “M” of the polymerizablemonomer [P-2] is hydrogen.

The polymerizable monomer [P-3] belongs to the compound III. “L_(m)” ofthe polymerizable monomer [P-3] is hydrogen. m=3. w=0. “R” of thepolymerizable monomer [P-3] is X₂-(Sp₂)_(v)-P₂ group. v=0. “X₁” and “X₂”of the polymerizable monomer [P-3] are single bond. “P₁” and “P₂” of thepolymerizable monomer [P-3] are group IX. “Y” of the polymerizablemonomer [P-3] is methyl.

The polymerizable monomer [P-4] belongs to the compound IV. “L_(m)” and“L_(n)” of the polymerizable monomer [P-4] are hydrogen. m=3. n=2. w=0.“R” of the polymerizable monomer [P-4] is X₂-(Sp₂)_(v)-P₂ group. v=0.“X₁” and “X₂” of the polymerizable monomer [P-4] are single bond. “P₁”and “P₂” of the polymerizable monomer [P-4] are the group IX. “Y” of thepolymerizable monomer [P-4] is methyl.

As to the mixture ratio of the liquid crystal molecules and thepolymerizable monomers, the weight of the polymerizable monomers isabout 0.1% to 10% of the total weight of the liquid crystalline medium.The weight of the liquid crystal molecules is about 99.9% to 90% of thetotal weight of the liquid crystalline medium. Preferably, the weight ofthe polymerizable monomers is about 0.3% of the total weight of theliquid crystalline medium, and the weight of the liquid crystalmolecules is about 99.7% of the total weight of the liquid crystallinemedium. More preferably, the weight of the compounds selected from thecompound 1 or 2 is about 30% of the total weight of the liquid crystalmolecules. The weight of the compounds selected from the compound 3 or 4is about 10% to 50% of the total weight of the liquid crystal molecules.The weight of the compounds selected from the compound 5 or 6 is about20% to 60% of the total weight of the liquid crystal molecules.

Moreover, the liquid crystalline medium further includes an initiatorwhose weight is about 0% to 0.002% of the total weight of the liquidcrystalline medium, for speeding up the polymerization reactions of themonomers.

A method for manufacturing a liquid crystal display panel according tothe present invention includes following steps. First, an uppersubstrate and a lower substrate are provided in a step (a). Next, thespace between the upper substrate and the lower substrate is filled withthe above-described liquid crystalline medium. Then, voltage is appliedto the upper substrate and the lower substrate, and an energy source isprovided in a step (c). As a result, the polymerizable monomers arepolymerized into alignment polymers. For example, the energy source isan ultraviolet source, a heat source or a combination thereof.

A liquid crystal display panel manufactured by above-described methodincludes the upper substrate, the lower substrate and a liquid crystallayer disposed between the upper substrate and the lower substrate. Theliquid crystal layer includes the above-described liquid crystalmolecules and alignment polymers. The alignment polymers are polymerizedby the polymerizable monomers through polymerization reactions andformed on at least one of the upper substrate and the lower substrate.The alignment polymers are for aligning the liquid crystal molecules orenabling the liquid crystal molecules to form pre-tilt angles.

A preferred embodiment is provided as follow for illustrating thecomposition, mixture ratio and manufacturing conditions of the liquidcrystalline medium. And then, the properties of the liquid crystallinemedium and the optical properties of the liquid crystal display panelare further analyzed.

The liquid crystalline medium of the preferred embodiment of the presentinvention includes the polymerizable monomers and the liquid crystalmolecules including chlorine. The liquid crystalline medium includes99.7% liquid crystal molecules and 0.3% polymerizable monomers. Theliquid crystal molecules in the liquid crystalline medium include thecompounds [2-1], [2-2], [2-3], [2-4] and [2-5] selected from thecompound 2, the compounds [3-1], [3-2], [3-3], [4-1] and [4-2] selectedfrom the compound 3 or 4, and the compounds [5-1] and [5-2] selectedfrom the compound 5. The polymerizable monomers include the compound[P-1].

A control group (i.e. another liquid crystal medium comprising the samepolymerizable monomers yet the liquid crystal molecules withoutchlorine) is used as a standard for comparison.

After analyzing the properties of the liquid crystalline medium of thepresent embodiment and the control group, it is found that these twoliquid crystalline media are similar in the optical anisotropy,dielectric anisotropy, nematic-isotropic phase-transition temperature(Tni), etc. However, rotational viscosity of the liquid crystallinemedium of the present embodiment is only 77.4 mPa*s, which is far belowthe rotational viscosity of the control group, 141 mPa*s. Therefore, theliquid crystalline medium of the present embodiment has less resistancewhen rotating, which can reduce the response time.

Then, the space between the two substrates is filled with theabove-described liquid crystalline medium, and a voltage of 6.4 J isapplied between the two substrates. After the liquid crystal moleculesand the polymerizable monomers are arranged according to the electricfield, an ultraviolet source is used for polymerizing the monomers intoalignment polymers. The liquid crystal display panel of the presentembodiment is accomplished accordingly. In addition, the liquid crystaldisplay pane of the control group is manufactured by the same method,except for that the liquid crystalline medium has no chlorine.

Optical performance experiments are performed on the liquid crystaldisplay panels of the present embodiment and the control group.

After different values of voltage are applied to the liquid crystaldisplay panels, the turn-on time (T_(on)), which is time that the liquidcrystal molecules need to rotate from the initial position to thepredetermined position, is measured and illustrated in FIG. 1.Furthermore, after stop applying voltage, the turn-off time (T_(off)),that is time the liquid crystal molecules need to return to the originalposition, is measured as well and illustrated in FIG. 2.

Please refer to FIG. 1. When the voltage is equal to 5.5V, the responsetime (i.e. T_(on)) that the liquid crystal molecules in the liquidcrystal display panel of the present embodiment need to rotate from theinitial position to the predetermined position is equal to that of thecontrol group: When the voltage is greater than 5.5V, the response time(i.e. T_(on)) that the liquid crystal molecules in the liquid crystaldisplay panel of the present embodiment need to rotate from the initialposition to the predetermined position is much less than that of thecontrol group. Please refer to FIG. 2. No matter how much voltage isapplied, the response time (i.e. T_(off)) that the liquid crystalmolecules in the liquid crystal display panel of the present embodimentneed to rotate back to the original position is less than that of thecontrol group. When the liquid crystal display panel of the controlgroup is driven by the voltage of 5.5V, the turn-on time (T_(on)) is10.8 ms, and the turn-off time (T_(off)) is 9.2 ms. When the liquidcrystal display panel of the present embodiment is driven by the voltageof 5.5V, the turn-on time (T_(on)) is 10.8 ms as well, but the turn-offtime (T_(off)) is only 7.8 ms.

Furthermore, the contrast ratio of the liquid crystal display panel ofthe preferred embodiment is 3443, which is similar to 3609, the contrastvalue of the liquid crystal display panel of the control group.Therefore, when the optical properties remain the same, the liquidcrystal display panel of the present embodiment has shorter responsetime. The optical performance of the liquid crystal panel is improvedeffectively.

In the liquid crystalline medium, the liquid crystal display panel usingthe same, and the method for manufacturing the liquid crystal displaypanel according to the above embodiment, the polymerizable monomers andthe liquid crystal molecule including chlorine have lower viscosity.Therefore, the resistance that the liquid crystal molecules have whenrotating is less, and the response time is shorter. It is proofed fromthe above embodiment that the liquid crystalline medium of the presentembodiment has much lower viscosity than the conventional liquidcrystalline medium. The liquid crystal panel using the liquidcrystalline of the present embodiment has the same optical propertiesbut shorter response time. Therefore, the optical performance of theliquid crystal display panel of the present embodiment is better.

While the invention has been described by way of example and in terms ofa preferred embodiment, it is to be understood that the invention is notlimited thereto. On the contrary, it is intended to cover variousmodifications and similar arrangements and procedures, and the scope ofthe appended claims therefore should be accorded the broadestinterpretation so as to encompass all such modifications and similararrangements and procedures.

1. A method for manufacturing a liquid crystal display panel, the methodcomprising: providing an upper substrate and a lower substrate; fillinga space between the upper substrate and the lower substrate with aliquid crystalline medium, the liquid crystalline medium comprising aplurality of liquid crystal molecules and a plurality of polymerizablemonomers, the liquid crystal molecules selected from at least one ofcompounds 1 and 2, the compound 1 represented as formula:

the compound 2 represented as formula:

and selected from at least one of compounds 3, 4, 5 and 6, the compound3 represented as formula:

the compound 4 represented as formula:

the compound 5 represented as formula:

and the compound 6 represented as formula:

wherein “G¹”, “G³” and “G⁵” are independently alkyl having 1 to 8carbons or alkyenyl having 2 to 8 carbons, “G²” and “G⁶” areindependently alkyl having 1 to 8 carbons or alkoxy having 1 to 7carbons, “G⁴” is alkyl having 1 to 8 carbons, alkyenyl having 2 to 8carbons or alkoxy having 1 to 7 carbons, “Z¹” is single bond, ethyl(—C₂H₄—) or methoxy (—CH₂O—), “Z²” is single bond, ethyl (—C₂H₄—),methoxy (—CH₂O—) or caroboxyl (—COO—), “Z³” is single bond, ethyl(—C₂H₄—), difluoromethoxy (—CF₂O—), difluoropropoxy (—OCF₂C₂H₄—) orethyl carboxyl (—C₂H₄COO—), “Z⁴” is single bond, ethyl (—C₂H₄—),difluoromethoxy (—CF₂O—) or difluoropropoxy (—OCF₂C₂H₄—),

are independently 1,4-cyclohexylene or 1,4-phenylene, and one of “E¹”and “E²” is fluorine, and the other is chlorine; and applying voltage tothe upper substrate and the lower substrate, and providing an energysource for polymerizing the polymerizable monomers into an alignmentpolymer.
 2. The method according to claim 1, wherein the polymerizablemonomers are selected from at least one of compounds I, II, III, IV andV the compound I represented as formula:

the compound II represented as formula:

the compound III represented as formula:

the compound IV represented as formula:

the compound V represented as formula:

wherein “R” is hydrogen, fluorine, chlorine, cyano group (—CN),thiocyanato (—SCN), pentafluoro-sulfanyl (—SF₅), nitrite (—NO₂),straight chain or branched chain alkyl group having 1 to 12 carbons or a“X₂-(Sp₂)_(v)-P₂” group, wherein v≧0; “X¹” and “X²” are independentlyoxygen, sulfur, methyoxy (OCH₂—), carbonyl (C═O), caroboxyl (—COO—),carbamoyl (—CO—N0R—, —N⁰R—CO—), methylthio (—CH₂S—, —SCH₂—),ethenylcarbonyl (—CH═CH—COO—), carbonylethenyl (—COO—CH═CH—) or singlebond, “Sp₁” and “Sp₂” are independently a spacer group or single bond,“L_(m)” and “L_(n)” are hydrogen, fluorine, chlorine, cyano group,alkyl, alkylcarbonyl, alkoxycarbonyl, or alkylcarbonyloxy having 1 to 7carbons respectively; wherein m≧1 and n≧1, “Q₁” and “Q₂” areindependently oxygen, sulfur, (carbonyl, C═O), caroboxyl (—COO—),methyoxy (—OCH₂—), methylthio (—CH₂S—), ethenylcarbonyl (—CH═CH—COO—),carbonylethenyl (—COO—CH═CH—), difluoromethoxy (—CF₂O—, —OCF₂—),difluoro methylthio (—CF₂S, —SCF₂—), ethyl (—C₂H₄—), difluoroethane(—CF₂CH₂—, —CH₂CF₂—), tetrafluoroethane (—CF₂CF₂—), vinylene (—CH═CH—),difluoroethenylene (—CF═CF—), ethynyl (—C≡C—) or single bond, and “P₁”and “P₂” are two polymerizable groups respectively.
 3. The methodaccording to claim 1, wherein the polymerizable group is selected fromone of groups VI, VII, VIII, IX and X, the group VI represented asformula:

“U” selected from hydrogen, methyl, fluorine, trifluoromethyl (—CF₃) andphenyl, the group VII represented as formula:

“T” selected from hydrogen, methyl, fluorine, trifluoromethyl (—CF₃) andphenyl, the group VIII being pyrrole-2,5-dione, represented as formula:

the group IX represented as formula:

“Y” selected from hydrogen, methyl, fluorine, trifluoromethyl (—CF₃) andphenyl, and the group X represented as formula:

“M” selected from hydrogen, methyl, fluorine, trifluoromethyl (—CF₃) andphenyl.
 4. The method according to claim 1, wherein the weight of thepolymerizable monomers is about 0.3% of the total weight of the liquidcrystalline medium.
 5. The method according to claim 1, wherein theliquid crystal molecules comprise at least three compounds, the liquidcrystal molecules comprising at least one selected from the compounds 1or 2 and the weight thereof being about 30% to 70% of the total weightof the liquid crystal molecules, at least one selected from thecompounds 3 or 4 and the weight thereof being about 10% to 50% of thetotal weight of the liquid crystal molecules, and at least one selectedfrom the compounds 5 or 6 and the weight thereof being about 20% to 60%of the total weight of the liquid crystal molecules.
 6. The methodaccording to claim 1, wherein the liquid crystalline medium furthercomprises an initiator whose weight is substantially 0% to 0.002% of thetotal weight of the liquid crystalline medium, for polymerizing thepolymerizable monomers into the alignment polymers faster.